Process for heating and bending metallic printing plates, such as stereotype and electrotype plates



March 8 1927. 1,620,042

c. N. SMITH PROCESS FOR HEATING AND BENDING METALLIC PRINTING PLATES,SUCH AS STEREOTYPE AND ELECTROTYPE PLATES Original Filed April 24. 1922Uhil'lE,

sT-Arss 11,62,042 PATENT vorricizz.

CHRISTIAN N. SMITH, OF ELGIN, ILLINOIS, ASSIGNOR 0F ONE-HALF TOXVILLIAM' I. TOPPING, 0F ELGIN', ILLINGIS; ALICE MINNIE SMITH AND LILYIRENE SMITH EXECUTRICESxGF; SAID CHRISTIAN" N. SMETH, DECEASED.

EROCESS FGR HEATING BENDING METALLXC PRINTING ?LATES, SUCH ASSTEREO'EYPE'AND ELECTROTYPE PLATES.

Original application filed April 24, 1922, Serial No. 558,310. Dividedand, this application filed r 17, 1925. Serial no, 63,114. v

This invention relates to that class of processes for heating andbending metallic printing plates, whereby printing plates, such aselectrotype and stereotypeplates may be bent or heated andbent'intosuitably curved form for use in printing.

The principal object of the invention is to provide a simple, economicaland efficient process for heating and bending metallic printing plates,such as electrotype or stereotype plates.

'Qther and further objects of the invention will appear from thefollowing description and claims, and from an inspection of theaccompanying drawings, which are made a part of this specification.

The invention consists in the improved method or process of bending ormoistening, heating and bending metallic printing plates, such aselectrotype and stereotype plates, whereby such printing plates may bebent into suitably curved form for use in printing.

This application 13 a division of a pendapplication Serial No. 556,310-,filed in the United States Patent ()fiice by me and in my name on April24-, 1922, for improvements in machines and processes forbendingmetallic printing plates, such as stereotype and electrotypeplates, and a continuing up lication in part of said application and ofa pending application Serial No. H1397, filed in the United StatesPatent Office by me and in my name on May 5, 1925, for inn'irovements inmachines and processes for heating and bending metallic printing plates,such as electrotype and stereotype plates.

in the accompanying drawings- Figure l is a view in front elevation of amachine adapted to be used in the process or method of heating,moistening and bending metallic printing plates in accordance withnay-improved process and invention, the hollow heating and bending rollbeing shown in vertical section, and the metallic printing plate andmetallic backing sheets October verse section as they would appear whilepassing between the rolls in the process of being-heated and bent;

Fig; 2 a, View in side elevation of the" machine shown in Fig. 1, withparts broken away, and with the driving and heating mechanism forheating and driving the heating and bending roll omitted;

Fig 3 is a detail view in perspective of a hollow heating and bendingroll, with a metallic printing plate, a sheet of moisture containingcompressible material, such as moist paper pulp in contact with theprinting side of the printing plate, flexible outer and intermediatemetallic backing sheets, and intermediate sheets of compressible ma,-terial between the metallic backing sheets, and between the innermetallic backing sheet and the moisture-containing sheet, all shown inposition as they would appear when pass ing between the hollow heatingand bending roll and an opposed forming roll in the operation otbeingheated and bent; and

Fig. l shows a metallic printing plate, with a moisture-containingcompressible sheet in contact with its printing side, two metallicbacking sheets in contact with each other, and intermediate sheetmaterial between the inner metallic backing sheet and the moist sheet.

In bending, or heating, inoisteningand bending metallic printing plates,such as electrotype and stereotype plates, by and in accordance with myimproved method or process, I employ a suitable machine or heating andbending apparatus'which may be in the form of the'machine shown anddescribed in either of. the above mentioned pending applications, or ofother suitable form.

' I provide,ftor example, a bending, or h .at-

ing, moistening and bending machine which,

in theiorm shown in the accompanying drawings, comprises a main frame 1,which maybe of any desired ordinary andwell known or suitable formadapted to support the working-parts of the machine. The

frame shown in the drawings is provided Bemovably mounted and journaledin suitable bearings in the standards or upright frame members 2 is ahollow heating and bending roll 4 having a curved or cylindrical outerperipheral wall 5, end walls 6, hollow endwise projecting hubs orjournals 7 at each end of said roll respectively and rotatively mountedor journaled in suitgble bearings in said upright frame memers. V

The upright frame members or standards 1 2- are each provided with arecess or slot axle or trunnions 13 at t adjusting the roll.

8 having marginal top and bottom walls or margins 9 and 10, adapted toadmit the axles or hubs 7. Bearing blocks or journals bearings 11secured to the standards 2 are adapted to removably support the rotativeheating and bending roll 4 in position in the frame.

Mounted adjacent to and with its cylindrical periphery in parallelrelation to the peripheral surface of the heating and bending roll 4, isa supplementary or auxiliary bending roll 12, of which there may be oneor more. The axes of the rolls i and 12 are parallel, and the roll 12 isprovided with an he opposite ends of the roll, said axle or trunnionsbeing rotatively mounted in sliding bearing blocks li which are slidablymounted between parallel ways or guides 15', 15, formed by the uprightstandards 2 adjacent to the opposite ends of the rolls.

Suitable means for adjusting the sliding blocks 14 and thereby the rollor rolls 12 is provided which may be of any desired ordinary and wellknown or suitable form.

For example, each sliding block 1% is pro-- vided with an adjustingscrew 16 non-rotatively mounted in or fixed to and movable upward anddownward with such sliding block, the upper ends of said screws beingscrew-threaded A toothed bevel gear 17 is mounted in screw-threadedengagement with each adjusting screw 16 and rotatively supported in asuitable bearing 18 in the corresponding side frame member or standard2. Each of the bevel gears 17 has a collar of flanged hub portion 19adapted to abut against the under side of the bearing 18, so as topermit the rotation of the gear but prevent the movement of the samelongitudinally of its axis. A shaft 20 1S rotatively mounted andprovided with bevel gear wheels 21 fixed to its opposite ends, each intoothed engagement with an adjacent bevel gear wheel 17. find a handwheel 22 fixed to the shaft 20 serves as a convenient means for rotatingsaid shaft in the operation of Heating and bending rolls of varying orunequal diameters may be used successively or interchangeably.

Means is provided for heating the hollow heating and bending roll l,which heating means may be of any desired ordinary and well known orsuitable form, such, for eX- ample, as a steam pipe or gas pipe leadinginto the interior of the roll through the hollow axle and adapted tocommunicate with.

a suitable source of steam or gas supply, as the case may be, said rollhaving suitable discharge openings for permitting the escape ofexhausted steam or products of combustion. Iprefer, however,-to employgasburning heating means, in order to obtain the required or desiredhigh temperature which is best suited for the purpose.

Each heating and bending roll 4 forms an inner heating or combustionchamber 23 into which leads an axial end opening 24, which may be in oneof the hollow hubs or journals 7.

A supply pipe 25 is provided which extends into the inner heating orcombustion chamber and communicates with a source of steam or supply. Inthe form of device shown in the drawings the supply pipe 25 is adaptedto communicate with a gas supply or fuel supply and is adapted todischarge gas or hydrocarbon fuel into the adjacent spaced-apart end ofa conduit or burner tube member 26 which has a cup 27 on its outer endand adapted to surround the adjacent discharge end of the pipe 25.

In the form of the device shown in the drawings a plurality ofperforated branch pipe or burner members 28 are provided which areinside of the heating or combustion chamber of the roll a and connectedwith the tube 26. A gas burner is thus formed which is adapted tooperate like a Bunsen burner on the inside of the heating chamber of thehollow heating and bending roll, which is by preference, provided withan inner hollow drum 29 which is concentric with the roll a and forms acylindrical or annular wall inside of said roll. The drum 29 thus formsthe inner wall of the annular heating or combustion chamber 23 in whichthe gas burner is located. And the combustion chamber is, of course,provided with suitable discharge openings, for permitting the escape ofproducts of combustion, and with suitable air-inlet openings 30 for theadmission of air to the combustion chamber.

Suit-able driving means is provided, for driving the hollow heating andbending roll 4, which may be of any desired ordinary and well known orsuitable form.

For example, a driving shaft 31 is journaled in suitable bearings 32,and provided with clutch mechanism 33 including a clutchoperating lever34 and a movable clutch member 35 on said driving shaft and movable intoand out of clutching engagement with a clutch member 36 on the end ofthe roll 1, all adapted to detachably connect the driving shaft 31 withsaid roll.

A worm wheel 37 is fixed to the driving lGU shaft 31 andta. main.drivingor .worm shaft 38 is mounted in. suitable bearings and providedwith a worm 39 fixed to said shaft 38 and adapted to engage the wormwheel 37 on said driving; shaft 31.

The rolls 4 and 12 may be either so mounted that their axes areverticalas shown in application 556,310 above referred to, or so mounted thattheirzaxesaare horizontal, as shown in application No. 711,297. And theymay be heated by either steam or by means of a gas burner, though Iprefer the latter as already stated.

The hollow heating and bending roll 4 is provided with peripheral.printing-plateengaging bar 44 which extends longitudinally of the rolland, by preference, from endto end thereof and in parallel relationtothe axis of the roll.

The plate-holding strip or bar 44 is provided with a side flange 45which projects over a corresponding inner longitudinal marginal notch orrecess 46. which is adapted to receive and removably hold in positionthe corresponding adjacent marginal portion or edge of a metallicprinting plate, such as an electrotype or stereotype plate 47 to be bentor heated, moistened and bent. The marginal-fiange-45 projects over theadjacent marginal portion of the metallic printing plate and acts toremovably but firmly hold said margin between the flange and theadjacent peripheral surface of the roll 4 during the operation ofheating and bending the plate. An outer-flexible sheet or backing plate48, which is by preference, made of flexible sheet metal, extends overthe, outside of the plate-holding bar 44 and from end to endv of saidbar, and has its forward edge secured to the peripheral surface of theheating and bending roll 4, in engagement with the bar 44 and roll, inadvance of the said bar, by suitable securing means, such, for example,as a securing strip 44 riveted in place or otherwise secured to thebacking plate 48 and its support.

The flexible outer metallic backing plate or sheet 48 is of sufiicientlength to completely or approximately encircle the heating and, bendingroll on which it is mounted. A similar inner flexible metallic backingsheet 49 is mounted intermediate the outer flexible backing sheet 48 andthe metallic printing plate to be bent, or between the outer backingsheet 48 and the periphery of the heating and bending roll in positionto extend outside of the metallic printing plate during the operation ofheatingand bending the same. An intern'iediate-sheet of relatively thickcompressible elastic or rubbery material 50, such, for example as asheet or sheets of Part. rubber, composition containing rubber, orsimilar compressible material, is.

mounted between'the metallic backing" sheets 48 and 49, and is adaptedto yieldingly resist pressure applied to the outer side of the outermetallic backing sheet 48, and to permit the metallic sheets 48 and 49to be pressed inward toward the metallic printing plate during theoperation of heating and bending the same; but said elastic sheet 50acts to hold said metallic plates 48, 49in yielding relation to eachother and spaced apart from each other. And the said metallic plates 48,49 act to prevent the rubbery compressible or elastic cushioning sheet50 from crawling and from spreading in direct contact with the sheet orcompressible material which is to be interposed between the outerbacking sheet-s 48,49, 50, and the metallic printing plate. The sheets48, 49, 50 may be said to form an armored backing or laminated plate orset of backing sheets which have the quality of being compressiblewithout causing or permitting either of the outer layers thereof tospread or crawl in the operation of heating and bending and moistening ametallic printing plate. The cushioning sheet 50 may be approximatelyhalf an inch in thickness, more or less, and is adapted to be compressedbetween the metallic sheets 48, 49, and thereby made much thinner thanwhen in normal condition, without injury to the compressible sheet. Asheet or sheets of compressible material should be placed between theprinting surface of the printing plate and the metallic sheet materialor armored compressible and elastic backing material or sheets abovedescribed. j V

In practicing my improved process of bending or heating. moistening andbending metallic printing plates, such as electrotype or stereotypeplates, copper printing plates, zinc, or aluminum plates, or printingplates of an desired material, ll provide a metallic printing plate 47,which maybe an electrotype or a stereotype plate. The printing plate isprovided on its printing side with a; covering or layer, sheet or sheets51 of compressible material, such, for example, as a sheet of paperpulpor similar compressible material in a moist or plastic condition.This moishire-containing sheet is laid upon and in-contact with theprinting side of the metallic printing plate and is adapted to betightly COIUPI'GSSQd against said. printing side or face of saidprinting plate, and, by preference, heated and dried or partially dried,so as to fill all of the recesses, inter stices and depressions in theprinting. surface or side of the printing pfate and moisten the same,and form what may be tern' ed a temporary matrix which is made, compressed While in a moist or plastic condition, progressively bent anddried or partially dried and bent with the printing plate during theoperation of heat-ing, moistening and bending said print-in plate.

The heating, moisteningand bending of the metallic printing plate andthe heating and bending of the sheet 51 of compressible material in amoist or plastic condition is accomplished while the compressiblematerial or sheet 51 is in contact with the printing side of theprinting plate. lhe sheet 51 of compressible matrix-forming materialthus laid on the printing side of the printing plate in a moist orplastic condition, is covered with a sheet of suitable compressiblematerial 52, such as wool felt or similar fibrous compressible material,which may be in dry condition, and is adapted to absorb moisture fromthe matrix-forming or moisture-containing sheet with which said sheet 52is in contact. Or the sheet 52 may be of blotting paper or similarabsorbent material.

A. flexible sheet of suitable material which is, by preference, somewhatharder than the sheet 52, and which may be in the form of a sheet 53 offlexible hard rubber, rubber composition, or similar flexible material,which may be water-proof. laid on the sheet 52 and between said sheet 52and the inner metallic sheet d9 above described, said metallic sheet 49bcing laid on the sheet 53, and said cushioning sheet 50, hard rubher orsimilar compressible material being laid on the metalli sheet 49 andbetween said metallic sheet and the outer backii'ig sheet 48 which is,by preference, permanently secured to the periphery of the heating andbending roll 4 as already described. The whole of said elements orsheets, and the metallic printing plate to be heated, moistened andbent. are thus placed together and in position to pass between the rolls4 and 12, with the edge of the metallic printing plate 47 in the slot ornotch l6 and between the flange on the plate-holding bar id and theperiphery of the heating roll. All of said elements are thus placedbetween the hollow heating and bending roll a and the outer metallicbacking sheet 48 fixed to said 7 roll 4. The metallic printing plate isthen heated .to the desired temperature, which may be accomplishedbyheating the roll 4 with which the inner face ot the printing plate is incontact. to the desired temperature to enable the metallic printingplate to be moistened and bent while heated, to the desired curvature.

The rolls are then rotated slowly, so as to cause the metallic printingplate, the outer temporary-matriX-forming element is thus heated andcompressed and bent while in a moist or plastic condition and in contactwith the printing face of the metallic printing plate, so as to fill allof the interstices and depressions in the printing side or face of saidprinting plate; and said lIlOlSlJlltC-Umltaining sheet and metallicprinting plate are heated and bent together or simultaneously andprogressively while in a heated condition and while the sheet 51 is in amoist or plastic condition and in position to act to moisten theprinting side or face of the metallic printing plate during theoperation of heating and bending the same progressively.

The metallic printing plate and the moisture-containing sheet in contacttherewith are then allowed to cool, and the moisturecontaining sleet isallowed to dry or to become partially dry while in contact with theprinting side of the printing plate which is also, by preference,allowed to cool progressively so as to become set in its properly curvedcondition. The curved metallic printing plate is then removed from the heating and bending roll and the temporary-inatrix-iiorming sheet ormoisture-conraining sheet 51 removed from the bent or curved printingsurface of the metallic printing plate thus heated, moistened, dried orpartially dried and bent. And the operation is repeated in the bending,or heating moistening and bending of other or similar metallic printingplates, as desired. The same hollow hcating'and bending roll may be usedrepeatedly; or hollow heating and bending rolls of difi'erent diametersor sizes may be used successively or interchangeably,

,or as desired.

I have found in practice that, in order to obtain the best results, theheating roll and printing plate should be heated to a very hightemperature such as is not readily obtainable by other means than by aburner, such as a gas burner adapted to heat the heating chamber formedinside of the roll. The moisture-containing material should be heatedand compressed against the metallic printing plate while thecompressible material is in a moist or plastic condition, andsimultaneously with the heating and bending of the metallic printingplate, and dried or partially dried progressively and during theoperation of heating and bending the print ing plate, which is, bypreference allowed to cool and set while held firmly in place upon theheating and bending roll and. while in contact with the sheet oicompressible moi:- ture-containing or temporary-matriX-forming material.V r

In Fig. 4 is shown a metallic printing plate 47 on and in contact withthe printing side of which is laid a sheet of moisturecontainingcompressible material 51 of paper pulp orsimilar material in a moistorplastic condition. And a sheet 53 of hard rubber or similar flexiblematerialis laid directly uponand in contact with the lllOlStllI'G-COihtaining sheet 5l and between said sheet 51 and a metallic backing sheet49 which is mounted in engagement with the inner face of an outermetallic backing sheet or plate as and is adapted to be held bythelatter inengagemcnt with said adjacent intermediate strip or sheet 53 ofrubber or similar material softer than metal and flexible. The outerflexible backing sheetor plate 428, of flexible sheet metal shown in.Fig. 4:, is adapted to extend over the outside of the printing-plateholding-bar l i and from end to end of said bar, and has its 'lorwardedge secured to the peripheral surface of the leatir j and bending rollat as already described, or to such heatingand bending roll, whethersteam-heated or gas-h eated, as may be employed in the practice of? theprocess in accordance with my invention. The sheet Slotmoisture-containing compressible mate 'ial thus forms a filler whichfills the inter stuns and depressions in the printing side of theprinting plate, and serves to moisten the printing plate and prevent itfrom becoming over-heated.

A coating of whiting or similar finely divided material in a moist orplastic condi tion may be interposed between the moisture-containingsheet 51 and the printing side of the printing plate, if desired; orstrips or" moist paper pulp or similar material may be laidin contactwith the printing side of the printing plate to fill some of thedepressions or interstices in the plate, such strips being covered bythe sheet 51, but I have found in practice that very satisfactoryresults can be accomplished without such strips or finely dividedmaterial.

Some printing platesfor example, electrotype platescan be bent whilecold, or without being artificially heated to a high temperature, byplacing in contact with the printing side of such printing plate a sheetof moisture-containing material, such as sheet 51, adapted to moistenthe plate and fill the interstices and depressions in the printing sidethereof, and simultaneously and progressively compressing and bendingthe 1noisture-containing sheet and printing plate together between aforming roll. and one or more metallic backing sheets, by preference,with intermediate absorbent sheet material and rubber sheet-s betweenthe metallic backing sheet and the printing plate. This may beaccomplished by passing the printing plate and moisture-containingsheet, and metallic backing plates and intermediate sheets betweenforming rolls, or between a forming or bending roll and a bed orequivalent means for compressing and bending the printing plate andmoisture-containing sheet together while the metallic backingsheet orsheets are stretched or held at a tensionin position to enable therequired pressure or compression to be obtained progressively asrequired.

I claim:

1. A process of bending metallic printing plates, which comprisesplacing in contact with the printing side of a printingplate a layer orsheet of moisture-containing compressible material adapted to becompressed into engagement with the interstices and depressions in andto moisten the printing side of such plate, and then compressing themoisture-containing material into said depressions, thereby filling thede JL'GSSlOIlS in and moistening the printing side of the printingplate, and simultaneously bending the engaged moistare-containingcompressible material and moistened metallic printing plate together.

2. A process of bending metallic printing plates, which comprisesplacing in contact with the printing side of a printing plate a sheet ofmoisture-centsining flexible n1aterial adapted to be compressed intoengagement 'ith the interstices and depressions in and to. moisten theprinting side of such printing plate, and then compressing themoisture-containing material' into said depressions, thereby filling thedepressions in and moistening the printing side of the printing plate,and simultaneously and progressively bending the' engagedmoisturecontaining material" and moistened metallic printing platetogether, and then removing the said sheet of flexible material from theprinting side of the printing plate.

3. A process of bending metallic printing plates, which comprisesplacing in contact with the printing side of a printing plate a sheet orlayer of moisture-containing flexible material adapted to be compressedinto engagement with the interstices and depressions in and to moistenthe printing side of such printing plate, then filling the intersticesand depressions in and moistening the printing side of the printingplate by progressively compressing and bending the engagedmoisture-containing material metallic printing plate together, andheating the printing plate, and. then removing the sheet of flexiblematerial from the printing side of the printing plate.

4. A process of bending metallic printing plates, which comprisesplacing in contact with the printing side of a printing plate a sheet offlexible compressible material in a moist or plastic condition adaptedto engage and fill the interstices and depressions in the printing sideof such printing plate, and simultaneously and progressively heating,compressing and bending said sheet and metallic printing plate together.

5. A process of heating and bending. metallic printing plates, whichcomprises placand ing in contact with the printing side of a printingplate a sheet of flexible compressible fibrous material in a moist orplastic condition adapted to engage and fill the interstices anddepressions in the printing side of such printing plate, and thensimultaneously and progressively heating, compressing and bending saidsheet of fibrous material and metallic printing plate together.

6. A process of heating and bending metallie printing plates, whichcomprises placing in contact with the printing side of a printing platea moisture-containing sheet of Here ible compressible material adaptedto engage and fill the interstices and depressions in the printing sideof such printing plate, then heating and progressively compressing andbending said moisture-containing material and metallic printing platetogether, and then removing the sheet of flexible compressible materialfrom the curved metallic printing ilate.

7. A process of heating and bending metallic printing plates, whichcomprises placing in contact with the printing side of a printing platea sheet of moisture-containing flexible material adapted to engage andfill the interstices and. depressions in the printing side of suchprinting plate, laying a relatively dry sheet of absorbent material incontact with said moisture-containing material, and heating andprogressively compressing and bending the absorbent material,moisture-containing material and metallic printing plate together.

8. A process of heating and bending metallic printing plates, whichcomprises placing in contact with the printing side of a printing platea sheet of moisture-containing temporary-matrix forming pulp-likematerial adapted to engage and fill the interstices and depressions inthe printing side of such printing plate, laying a sheet or pad ofabsorbent material in contact with said moisture-containing material,then heating and progressively compressing and bending the absorbentmaterial, moisture-containing material and moistened metallic printingplate together, and then removing the absorbent material andplate-engaging sheet of pulplike material from the curved metallicprinting plate.

9. A process of heating and bending metallic printing plates, whichcomprises placing in contact with the printing side of a printing platea sheet of moisture-containing fibrous material adapted to engage andfill the interstices and depressions in the printing side of suchprinting plate, laying a sheet of absorbent fibrous material in contactwith said m0isture-containing material, then heating and simultaneouslyand progressively compressing and bending the absorbent material,moisture-containing fibrous material,

and moistened metallic. printing plate together, thereby partiallydrying the moisture-containing plate-engaging material, and thenremoving the absorbent material and plate-engaging sheet of fibrousmaterial from the curved metallic printing plate.

Signed at Elgin, in the county of Kane and State of Illinois, this 15thday of October,

CHRISTIAN N. SMITH.

